Abstract This paper reports a novel assembly method using multi-layer bonding technique for micro direct methanol fuel cells (μDMFCs) and their stacks. The new approach shows considerable merit on maneuverability and reliability, and is beneficial to decreasing the internal resistance of the μDMFC. The prototype of μDMFC assembled generates a high power density of 20.29mW/cm2 and a power of 45.6mW with high methanol concentration at room temperature. Benefiting from the assembly process, a new μDMFC tri-cell stack with an expandable cell amount is designed, fabricated and assembled, which has a maximum power of 86.92mW with 2M methanol concentration at room temperature. Moreover, this work presents a promising strategy for the assembly of microfluidic devices with laminated structures.